Procure a circular horizontal wheel two feet in diameter with a hole quite through the nave, then take four thin pieces of deal three feet long each, and three-quarters of an inch broad each. One end of each of these pieces is to be nailed to the felloe of the wheel at an equal distance from one another; and the other end nailed to a block with a hole in its bottom, which must be perpendicular with that in the block of the wheel, but not so large. The wheel being thus made, a hoop planed down very thin must be nailed to the felloe of the wheel, and wound round the four sticks in a spiral line from the wheel to the block at the top; on the top of this block a case of Chinese fire must be fixed, and on the wheel any number of cases, which must incline downwards and burn two at a time. The axis of the wheel must be a little longer than the cone, and made very smooth at the top, on which the upper block is to turn and the whole weight of the wheel to rest. The entire framing of the wheel, with its connecting tubes, is shown in the above [cut].
THE GRAND VOLUTE.
Should my young friends wish to prepare a grand volute illuminated with a revolving wheel; the first step is to procure a large circular wheel, and on its rim lay as many four-ounce cases as will complete the circle, only allowing a sufficient distance between the cases that the fire may pass free, which may be done by cutting the upper part of the end of each a little shelving. On each spoke fix a four-ounce case about three inches from the rim of the wheel. These cases are to burn one at a time. On the front of the wheel form a spiral line with strong wire, on which tie port-fires, placing them on a slant with their mouths to face the same way as the cases on the wheel; all these port fires must be fired with the second cases of the wheel. Let there be a series of wooden spokes all made to screw into a block into the centre. When the large wheel begins to discharge the fireworks, the spiral wheel will of course revolve and produce a very beautiful illuminated cone.
A BRILLIANT YEW-TREE.
To prepare a brilliant yew-tree, a frame like the one represented in the [drawing] must be firmly attached to the ground. When the branches are fixed, place illuminating port-fires on the top of each, as many as is convenient; behind the top of the stem fasten a gerb or white fountain, which must be fired at the beginning of the illumination on the tree. A series of these, varying in the angular directions taken by the boughs, produce a very fine effect.
